Hammer unions are well known in the in the oil, gas and mining industry. Hammer unions are used to fasten pipe together for low and high pressure applications and as is known, these unions typically include lugs or tabs which require engagement with a hammer for tightening and loosening. As is presently conducted in this field, a worker typically actuates the union by swinging a hammer. This applies a force to the tabs or lugs in order to rotate the union into a tightening or loosening position. As such, the lugs or tabs typically incur a significant amount of force from repetitive striking. One of the problems is that despite the fact that the lugs or tabs are obviously made of the same material forming the mechanical fastener or union, metal fatigue can certainly occur after repeated strikes. This can result in breakage of the lug or tab completely from the entire body of the fastener which would then result in the lug or tab becoming a projectile presenting a dangerous situation or fragments or pieces of the lug becoming dislodged from the lug itself, acting as shrapnel. These are serious issues and can result in injury to not only the worker operating the hammer, but also surrounding members of a work team. A further problem that exists with this type of system is that the swinging of an object towards the hammer union can present a hazardous situation, particularly where a worker is not alert to his surroundings.
In order to circumvent this problem, a number of solutions have been proposed in the prior art, one of which is indicated in United States Patent Publication No. US 2012/0048069, with the published author being named as Powell Jr. In the publication, it is disclosed that the Applicant provides a hammer union wrench comprising a tool head having a substantially circular or disk shaped tool head body with an opening there through axially and transversally. The axial opening also includes slots which receive tabs associated with the hammer union. Although this is a useful arrangement, it requires the engagement of at least two of the tabs or bosses of the hammer union and fairly specific alignment of the tool head relative to the hammer union. This is not an issue in situations where the union is free of any debris, but presents difficulties in use where the union has been exposed to debris or is encumbered by ice, snow, etc. A further perceived limitation to this arrangement is that there does not appear to be any compensation for adding or augmenting the torque that is applied to the union by the worker. The arrangement provides the head of the tool in direct alignment with a stock handle shown in the drawings as number 14. Accordingly, it would appear that the worker would still have to exert a significant amount of effort to activate the tool head in order to tighten or loosen the union.
Other arrangements that are known are spanner wrenches. An example of one such arrangement is shown in U.S. Pat. No. 2,830,480, issued Apr. 15, 1958 to Brame for a spanner wrench for tubing unions. Brame provides a wrench having a semicircular tool head with a series of recesses and projections positioned on the tool head. The recesses and projections mate in registration with similarly configured recesses and projections in the tubing union. This arrangement, similar to that set forth in the publication discussed supra requires precise alignment and potentially also has the possibility of slippage from the tubing union which could result in injury during use.
Earlier attempts in the art to improve the efficiency and overall construction of such wrenches is shown in U.S. Pat. No. 464,084, issued Dec. 1, 1891, to Robinson. The Patentee provides a curved jaw tool head with a tooth positioned within the jaw and guiding ears associated therewith.
In U.S. Pat. No. 2,691,912, issued Oct. 19, 1954, Jones provides an anvil type wrench. The wrench effectively comprises a body suitable for use in pipe union fittings.
The art has presented further variations on these overall arrangements. A further example of which is demonstrated in U.S. Pat. No. 1,528,892, issued Mar. 10, 1925 to Pigott et al. The patent provides for a wrench which has a U-shaped head internally directed towards portion 8.
In view of the limitations in the art, it would appear that there is still a need for a high efficiency wrench which does not require impact or regular forces to be applied to tabs or lugs of a pipe union or hammer union which causes premature ware and the hazards noted above. The present invention not only satiates these requirements but also provides for improved arrangement where torque can be applied to the tool with a greater degree of efficiency and less effort by the worker.